There has been developed recently a high density recorded disc, i.e. a video disc, in which the recorded information is in the form of a surface relief pattern formed along a spiral path in the major surfaces of the disc. Preferably, the surface relief pattern is formed in a spiral groove in the major surfaces of the disc. The disc includes a very large number of the grooves per radial inch, about 10,000 per inch, with the groove being very small, about 2.7 microns in width and on the order of 4000 Angstroms in depth. The record is played with a stylus which has a very fine tip which rides in the groove. One form of such a stylus is shown in U.S. Pat. No. 4,162,510 to E. O. Kaizer, issued July 24, 1979, entitled "KEEL-TIPPED STYLUS FOR VIDEO DISC SYSTEMS". During play of the record, the record is rotated at a relatively high speed, about 450 r.p.m. In order to reduce frictional forces and to prevent wear of the stylus and/or the record, it is desirable to provide a layer of lubricant on the surface of the record. The lubricant should be uniformly coated over the entire surface of the record but should be thin, preferably between 200 and 300 Angstroms in thickness, so that it does not interfere with the proper playback of the disc.
Because of the viscosity of the lubricant, it has been found difficult to achieve the desired thin, uniform coating of the lubricant on the disc. One technique which has been developed is to apply the lubricant with heptane as a carrier. The lubricant is mixed with heptane, about 0.3 part of lubricant to 100 parts of heptane. The mixture is then sprayed onto the surface of the disc by passing the disc under a series of oscillating nozzles which apply the mixture. After one side of the disc is coated, the disc is turned over to permit coating of the other side. Although this system satisfactorily applies a thin, uniform coating of lubricant on the surfaces of the disc, it has a number of disadvantages. The system requires the use of large quantities of heptane, which is expensive. Also, the heptane system must be handled with great care since heptane is toxic, flammable and explosive. In addition, the lubrication efficiency, i.e. the amount of the source lubricant which actually finally coats the disc, is very low. Therefore, it would be desirable to have a lubricant coating system which applies a thin, uniform film of lubricant onto the disc without the use of an expensive carrier material, particularly without heptane, and which has a high lubrication efficiency.